Brown azo dye and process of making same.



llNrrnn STATES ATENT OFFICE.

TO THE FARBENFABRIKEN "OF ELBERFELD COMPANY, OF NEW YORK.

BROWN Azo DYE AND PROCESS OF MAKING SAME.

sPEcIFIcAT'IONrm-min part of Letters Patent No. 658,507, dated September25, 1900.

Application filed December 28, 1899. Serial No. 741,849. (Specimens)with certain derivatives of metadiamidosulfonic acids of the benzeneseries-such as the mouomethyl, lnonoethyl, lnonobenzyl derivativesthereof-having the general formula R-NHR,

(R meaning a radical of a hydrocarbon of the benzene seriessuch asbenzene, toluene, or the like lt meaning an alkyl radical, such asmethyl, ethyl, benzyl, or the like.) The new dyestuffs thus obtained arealkaline salts of acids, having the general formula in which R means oneof the above-defined hydrocarbon radicals of the benzene series and R,an alkyl radical, such as methyl, ethyl, benzyl, or the like. They aredark powders soluble in water with a brownish-red color and dyeunmordanted wool in acid-baths in general from reddish brown to brownshades, which by a subsequent treatment with solutions of chromiumcompounds, such as potassium bichromate or the like, are changed intofast and deep-brown shades.

It may be remarked that the above-mentioned alkylatedmetadiamidosulfonic acids of the benzene series, such asmonomethylmetaphenylenediaminsulfonic acid or the like, can be preparedby the action of an halogen alkylsuch as methyl iodid, ethyl iodid,benzyl chlorid, or the likeon the said metadiamidosulfonic acids of thebenzene series.

In carrying out our new process practic-- ally we can proceed asfollows, the parts being by weight: 19.9 parts of picramic acid aredissolved in six hundred parts of hot Water, With-the addition of 8.5parts of ammonia liquor (containing twenty per cent. of NH After coolingit is diazotized in the known manner with the aid of seven parts ofsodium nitrite and a suitable quantity of hydrochloric acid. The d-iazoderivative which separates during this operation is isolated byfiltration and then stirred into a solution which has been prepared fromtwo hundred parts of water, 13.6 parts of sodium acetate, and 22.4 partsof the sodium salt of monomethylmetaphenylenediaminsulfonic acid (whichhas been produced by the action of one molecule of methyl iodid on onemolecule of the sodium salt of metaphenylenediamin sulfonic acid.) Themixture thus obtained is further stirred for about twelve hours.Subsequently it is heated to about 80 centigrade and then'mixed with asuitable quantity of common salt. Finally, the dyestufi thus separatedis filtered off, pressed, dried, and pulverized.

The new coloring-matter represents a dark 0 powder of a metallic luster,soluble in water with a brownish-red color. It is the sodium salt of anacid having the formula:

OH so n.

By concentrated sulfuric acid (of 66 Baum) Ioo it is dissolved, yieldinga dark-red solution, the color of which changes into reddish brown onthe addition of a small quantity of ice, while a reddish-brownprecipitate is separated therefrom on adding a larger quantity of ice.It is also soluble in ammonia witha brownishred color, in alcohol with adark-brown color.

The new dyestufi yields on unmordanted wool in acid-baths reddish-brownshades, which by a subsequent treatment with potassium bichiomate arechanged into deep-brown shades, fast to milling and to light.

Very similar results are obtained if instead of themonomethylmetaphenylenediaminsulfonic acid other of the above-defineddyestufi components are used.

Having now described our invention and in what manner the same is to beperformed, what we claim as new, and desire to secure by Letters Patent,is y l. The process for producing new monoazo dyestufls by firstcombining the diazo derivatives of picramic acid with certainderivatives of metadiamido sulfonic acids of the benzene series havingthe formula:

NH, RNI-IR,

so n

R meaning a radical of a hydrocarbon of the benzene series, B, an alkylradical, secondly isolating the dyestufis thus obtained substantially ashereinbefore described.

2. The process for producing a new monoazo dyestuif by first combining adiazo derivative of picramic acid withmonomethylmetaphenylenediaminsulfonic acid, secondly isolating thedyestulf thus produced, substantially as hereinbefore described.

3. The herein-described new monoazo dyestufis, being alkaline salts ofacids having the formula l O6H2N:N R-NHR,

on SOSH R meaning a radical of a hydrocarbon of the benzene series, R,meaning a radical of the which is a dark bronzy-colored powder, solublein water with a brownish-red color, soluble in concentrated sulfuricacid with a dark-red color which turns into reddish brown on adding asmall quantity of ice while a reddish-brown precipitate is obtained onthe addition of a larger quantity of ice to the sulfuric-acid solution,soluble in alcohol with a dark-brown color,in ammonia with abrownish-red color, dyeing unmordanted wool in acid-baths reddish-brownshades which by a subsequent treatment with a solution of potassiumbichromate are changed into deepbrown shades fast to milling and tolight, substantially as hereinbefore described.

In testimony whereof We have signed our names in the presence of twosubscribing witnesses.

PHILIPP OTT. Witnesses: FRANZ voLeER.

OTTO KGNIG, 4 J. A. RITTERSHAUS.

